I have quite a few documents in my notebooks that I need to reference only from time to time. This makes the document space a bit cluttered. Right now I will reorder the documents to have the most-used documents available in the first tabs.
This is an okay solution and more an idea for some time down the road. If I could simply hide documents form the tabs this might improve the experience a little. I could imagine grouping the documents by categories here as well and using this to hide/show entire categories of documents.